Construction of electric devices



Filed Aug. 3 192 Inventor.v Marcello Pirani,

bLJ His Attorney.

Patented Aug. 25, 1931 UNITED STATES PATENT OFFICE MARCELLO PIRANI, F BERLIN-WILMERSDORF, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, CORPORATION OF NEW YORK CONSTRUCTION OF ELECTRIC DEVICES Application filed August 3, 1926, Serial No. 126,873, and in Germany March 30, 1926.

The present invention relates to electrical devices having a hot filament, and more particularly to high current electric lamps, vacuum tubes and the like.

It is an object of my invention to provide electrical devices such as electric lamps with the neck made in sections of metal and a vitreous insulating material such as glass. Another object of the invention is to provide the metal sections of the neck with cooling devices and 'to fasten to these metal sections the lead wires which in the interior of the lamp, in the case of electric lamps, serve to support the filament. Furthermore, the lead Wires may be rigidly fastened to the cooled metal sections, thereby insuring rigidity and stability inasmuch as the usual sealing of leading-in Wires into glass is done away with.

The invention and its details will be more readily understood from the accompanying specification, claims and drawing, in which drawing the figure shows one form of an in candescent lamp in elevation and in section.

Referring more in detail to the drawing it will .be seen that the neck of the glass bulb 1' of the lamp comprises a metal annulus or short tube a constituting one terminal of the lamp and sealed between the glass tube or section aof the bulb on one side and the glass tube or section b of the neck on the other side, the lower part of the section I) being folded Within the neck to form a reentrant inner glass stem or tube Within the neck of the lamp there is a second metal tube 1 which is sealed at its outer end to the-glass stem 7 of the neck, so that its inner end is inside the neck and adjacent the metalannulus or short tube c, which may be threaded on the inside to support a ring (Z from which a'lead wire (1 projects into the bulb.

The tube or annulus c is also threaded on the outside to support a hollow cooling element, such as a tubular collar Z, th'ru which a liquid or other cooling medium may be caused prising a head it which closes air-tight the inner end of the tube g and from the outer side of which a metal pipe 70 projects to a' point outside the neck. From the inner side of said head 71. of the second terminal, a

second "lead wire 2' projects into the bulb. The filament s is connected to the two lead wires 6 and i to form a bridge between them. The metal tube 9 with the head it forms a skirt with its inner end adjacent the metal annulus orterminal 0 and its outer end hermetically sealed to the stem or tube f which forms part of the vitreous section b of the neck. The pipe 70 and the head it which closes it at its inner end form a hollow terminal having the shape of a deep cup placed inside of and concentric with the skirt 9. The pipe 70 has at its outer end a hollow cooling element or cap ;0 provided with. an inlet connection t and an outlet connection u for the purpose of causing a cooling medium, such as water, to flow thru the hollow terminal. The metal skirt 9 is secured by the head it to the inner end of the hollow terminal and extends along it, with the free end of the skirt directed toward the middle of the hollow terminal. The cap ;0 is provided with a binding post a which latter is in electrical connection thru the metal cap 72 with the metal pipe Z: of the hollow terminal and hence with the lead wire 2' within the lamp. Similarly the hollow collar Z is provided with a ing from the scope of the claims herein. For

example, in place of the elements shown. for water cooling there may be used an alr cooling-arrangement with ribs, ducts and the like.-

What I claimas new and desire to secure by Letters Patent of the United States, is,-

1. A high current hot filament device comprising a glass bulb having a neck, formed of a metal tube sealed between two tubular glass sections, one terminating in said bulb at one end and the other having one end sealed to said metal tube and the other end thereofmamas? the outer vitreous section of said neck and.

having its inner end positioned inside said neck adjacent said metal annulus, ahollow terminaliinside said skirt with its inner end joined to the inner-end of said'skirt, leads projecting from said terminals into said bulb, a filament connected between said leads, and cooling means-forcirculating a cooling fluid thru the interior of said hollow terminal.

In witness whereof, I have hereunto. set

my hand this 20th day of'July, 1926.

.MARCELLO PIRANI.

folded within said neck to form a tubular stem, a second metal tube within said first metal tube sealed to the end of said tubular glass stem within said neck, a filament within saidbulb mounted in bridge between said metal tubes, and a cooling element attached toeach of said metal tubes whereby they may filament on the outside of said neck, a terbe maintained cool by causing a cooling fluid to flow therethrough, said coolingelements serving asterminals forthe device.

2. A high current ho't filament device having a bulb with a. tubular neck, a filament located within said bulb, a terminal for said minal for said filament on the inside of said neck, a cooling element on the outside of said neck for cooling saidfirst terminal, and a cooling element for cooling said second. terminal. said cooling elements being hollow whereby a cooling fluid may be caused to circulate therethrough.

'3. An incandescent lamp or similar device comprising a bulb with a neck comprisingtwo tubular vitreous sections and a metal annulus between said vitreous sections with its ends hermetically sealed to said sections and constituting one terminal, a second terminal projecting into said neck and having the shape of a deep inverted cup with a metal head at the bottom of said cup, a tubular metal skirt joined airtight. at one end to said head to be concentric with and to extend along said second terminal with its other end opposite the middleypart of said second terminal and hermetically sealed to the outer one of said vitreous sections, a filament lead projecting from each of said terminals, and afilament connected between said leads.

4. An incandescent lamp or similar device comprising a bulb with a tubular neck comprising two annular vitreous sections and a metal annulus between said sections constituting a-terminal hermetically sealed at its end'to-said vitreous sections, a tubular metal I skirt hermetically sealed .at-its outer end to 

